BDNF and Alzheimer disease: Neurotrophic factors, which seem to be deficient in the AD brain, including Brain-derived Neurotrophic Factor (BDNF) (Castren and Tanila, 2006), Nerve Growth Factor (NGF) (Iulita et al., 2016) and Transforming-Growth-Factor-β1 (TGF-β1) (Wyss-Coray, 2006; Caraci et al., 2011a), have been proposed to limit the neurotoxicity of Aβ oligomers.